Modelling and Phenotypic Screening of NAP-6 and 10-Cl-BBQ, AhR Ligands Displaying Selective Breast Cancer Cytotoxicity in Vitro

To exploit the interaction of the aryl hydrocarbon receptor (AhR) pathway in developing breast-cancer-specific cytotoxic compounds, we examined the breast cancer selectivity and the docking pose of the AhR ligands (Z)-2-(2-aminophenyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NAP-6; 5) and 10-chloro-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one (10-Cl-BBQ; 6). While the breast cancer selectivity of 5 in vitro is known, we discuss the SAR around this lead and, by using phenotypic cell-line screening and the MTT assay, show for the first time that 6 also presents with breast cancer selectivity, notably in the triple-negative (TN) receptor breast cancer cell line MDA-MB-468, the ER+ breast cancer cell lines T47D, ZR-75-1 and the HER2+ breast cancer cell line SKBR3 (GI₅₀ values of 0.098, 0.97, 0.13 and 0.21 μM, respectively). Indeed, 6 is 55 times more potent in MDA-MB-468 cells than normal MCF10A breast cells (GI₅₀ of 0.098 vs 5.4 μM) and more than 130 times more potent than in cell lines derived from pancreas, brain and prostate (GI₅₀ of 0.098 vs 10-13 μM). Molecular docking poses of 5 and 6 together with analogue synthesis and phenotypic screening show the importance of the naphthalene moiety, and an ortho-disposed substituent on the N-phenyl moiety for biological activity.

Retrofitting an esthetic post and core to salvage a six-unit fixed partial denture

Teeth restored with post and core restorations present a clinical dilemma if they fracture. An individual with a maxillary anterior six-unit fixed partial denture had one of the canine abutment teeth fracture. The other abutment debonded and the post separated from the core. The fixed partial denture was salvaged by retrofitting a porcelain-fused-to-metal post and core restoration in the fractured abutment.

Rocuronium bromide in dental day case anaesthesia--a comparison with atracurium and vecuronium

We have compared intubating conditions at 60 seconds, onset times and reversal characteristics of the new steroidal nondepolarizing muscle relaxant rocuronium with atracurium and vecuronium. A dose of approximately 1.75 X ED90 of each agent was used to assess their relative suitability for brief day case dental procedures requiring intubation. The anaesthetic technique included propofol, fentanyl, nitrous oxide/oxygen and isoflurane. Electromyography was used to assess neuromuscular blockade. The percentage of good or excellent intubating conditions at 60 seconds was 80% for rocuronium but only 12.5% each for atracurium and vecuronium. The mean percentage block at 60 seconds was 55.1% for rocuronium, compared to 9.2% for atracurium and 8.3% for vecuronium. Rocuronium had the fastest onset time to maximum block (mean 313 sec) compared to atracurium (mean 391.9 sec) and vecuronium (mean 331.9 sec). The duration of action of rocuronium was shorter than either atracurium or vecuronium, times for spontaneous recovery to 75% block being 22.2 min, 29.6 min and 26.3 min respectively. The neostigmine evoked recovery indices were rocuronium 4.2 min, atracurium 6.6 min and vecuronium 3.7 min. Maximum blockade of greater than 97% was achieved with all three relaxants.